System and method for spray drying a liquid

ABSTRACT

Described herein are devices and techniques for spray drying a fluid to produce a dried powder. Assemblies include a spray drying head attachable to a gas supplier and a liquid sample, such as a standard unit of blood product. The spray drying head can be adapted to provide an aerosolized flow of liquid sample exposed to a drying gas. The assembly also includes a drying chamber adapted to separate the aerosolized flow of liquid sample into a dried powder and humid air. The assembly can be disposable, provided in a sterilized kit and having simplified attachments allowing quick connect and disconnect from the gas and liquid sample. Separation of the powder from the humid air exiting the drying chamber occurs within a filtered collection bag. In some embodiments, one or more of the drying chamber and collection bag are formed form a thin-walled, collapsible material.

RELATED APPLICATIONS

The present application is a divisional application of U.S. patentapplication Ser. No. 13/284,320, filed on Oct. 28, 2011, which claimspriority to U.S. Provisional Patent Application No. 61/408,438, filedOct. 29, 2010. The entire teachings of the above applications areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to devices and techniques forproducing and/or using spray-dried products, and more particularly tosuch devices and techniques for producing and/or using spray-driedproducts for treatment of a human.

BACKGROUND

Blood plasma is the yellow liquid component of blood, in which the bloodcells of whole blood would normally be suspended. Blood plasma makes upabout 55% of the total blood volume. Blood plasma is mostly water (e.g.,about 90% by volume) and contains dissolved proteins, glucose, clottingfactors, mineral ions, hormones, and/or carbon dioxide. Blood plasma isprepared by spinning a sample volume of fresh blood in a centrifugeuntil the blood cells fall to the bottom of a sample chamber. The bloodplasma is then poured or drawn off. Blood plasma is frequently frozenfresh for future uses. Although frozen plasma is the current standard ofcare, there are numerous problems with such techniques. For example, thebag containing the frozen plasma may become brittle and be damagedduring storage or transportation. Maintaining frozen plasma at theappropriate temperature during storage and transportation is veryexpensive. It requires mechanical freezers to keep the frozen plasma atabout −18° C. or lower. Shipping requires special shipping containers tomaintain the frozen state and reduce breakage of the bag. Use of thefrozen plasma is delayed by 30-45 minutes due to the thawing time.Moreover, the preparation for use requires trained staff and specializedthawing devices in a regulated laboratory. Finally, fresh frozen plasmahas a limited shelf life of 12 months at −18° C. Once thawed, the frozenplasma must be used within 24 hours.

In an attempt to avoid the disadvantages of frozen plasma, some havefreeze dried (i.e., lyophilized) plasma. However, the freeze dryingprocess produces a product composed of large, irregular sized grains orparticles. Such products can be difficult or impossible to rehydrate toa form suitable for administration to a patient. Furthermore, the freezedrying process requires transfer of the product from the lyophilizer tothe final container, thus requiring post-processing sterility testing.The freeze drying process can only be done in batch mode; continuousprocessing is not possible with freeze drying. Moreover, manufacturingscale-up requires changes to the freeze drying process, and there areprotein recovery issues at scale up.

Accordingly, a need still exists in the field for plasma that may bestored in a wide range of environments without freezers orrefrigerators, be available for use by first responders at the initialpoint of care, and can be transfused in minutes without the usual 30-45minute delay associated with thawing of frozen plasma.

SUMMARY

The devices and techniques described herein provide an extracorporeal,sterile, closed plasma processing system, which can be used to produce aspray dried, physiologically active plasma powder that has a longstorage life at room temperature; that can be easily stored and shipped;that is versatile, durable and simple; and that can be easily andrapidly rehydrated and used at the point of care. The processing systemcan produce spray dried powder in either a batch (e.g., single unit) ora continuous (e.g., pooled units) processing mode. The spray driedpowder can be dried directly into the final, attached sterile container,which can later be rapidly and easily rehydrated to produce transfusiongrade plasma. The spray dried powder can be stored for at least up tothree years at virtually any temperature (e.g., −180° C. to 50° C.). Thecosts associated with storage and shipping of the spray dried powder issignificantly lower, because of its lighter weight and broader range oftemperature tolerance compared to frozen plasma. At the point of care,the spray dried powder can be rapidly rehydrated in a transfusable form(e.g., 30-120 seconds), avoiding the need for special equipment andtrained staff. In contrast to frozen plasma, which takes 30-45 minutesto thaw and must be used within 24 hours, the spray dried powderobtained using the devices and techniques described herein avoids waste,since the caregiver can rapidly prepare the amount of rehydrated plasmarequired for a given patient, rather than trying to assess and predictthe amount of plasma required and thawing sufficient plasma to meet ananticipated need, which may have been an overestimate.

In one aspect, at least one embodiment described herein relates to aspray drying assembly. The spray drying assembly includes a spray dryinghead attachable to a gas supplier and a liquid sample. The spray dryinghead is adapted to provide an aerosolized flow of liquid plasma exposedto a drying gas. The assembly also includes a drying chamber adapted toseparate the aerosolized flow of liquid sample into a dried powder andhumid air. The drying chamber defines an elongated central lumen open atone end to receive the aerosolized flow of liquid sample and drying gas.The drying chamber is also open at an opposite end allowing fordischarge of dried powder and humid air. The assembly further includes acollection device. The collection device includes an inlet port in fluidcommunication with the opposite end of the drying chamber; a filteradapted to separate the dried powder from the humid air; and an exhaustport allowing humid air to exit the collection device.

In another aspect, at least one embodiment described herein relates to aspray drying chamber. The spray drying chamber includes an elongatedside wall extending between two open ends and defining a central lumenextending along a longitudinal axis. The chamber also includes areducing wall extending between an open widened end and an open narrowedend. The opened widened end is attached to one of the open ends of theelongated side wall. An attachment flange is attached to the opennarrowed end of the reducing wall and adapted for attachment to acollection device. The elongated side wall, reducing wall and attachmentflange define a fluid-tight open channel extending along thelongitudinal axis.

In another aspect, at least one embodiment described herein relates to aspray drying head. The spray drying head includes a spray-drying chambercover adapted to form a fluid-tight attachment to an open end of a spraydrying chamber. The spray drying head also includes a gas supplyinterface adapted to receive at least a relatively low-pressure flow ofheated drying air and a relatively high-pressure flow of aerosolizinggas. A fluid interface is adapted to receive a liquid sample; at leastone filter positioned to filter the flow of heated drying air. A nozzleis also provided and adapted to produce an aerosolized flow of theliquid sample.

In another aspect, at least one embodiment described herein relates to aspray drying collection device. The collection device includes an inletport in fluid communication with the opposite end of the drying chamberand a filter adapted to separate the dried powder from the humid air. Anexhaust port allows humid air to exit the collection device.

In yet another aspect, at least one embodiment described herein relatesto a process for spray drying a liquid. The process includesaerosolizing a flow of liquid sample. The aerosolized flow of liquidsample is exposed to a heated drying gas adapted for separating theaerosolized flow of liquid sample into a dried powder and humid air. Thedried powder is then filtered from the humid air.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages will beapparent from the following more particular description of theembodiments, as illustrated in the accompanying drawings in which likereference characters refer to the same parts throughout the differentviews. The drawings are not necessarily to scale, emphasis instead beingplaced upon illustrating the principles of the embodiments.

FIG. 1 illustrates a schematic diagram of an embodiment of a spraydrying and collection assembly.

FIG. 2 illustrates a schematic diagram of another embodiment of a spraydrying and collection assembly.

FIG. 3 illustrates a schematic diagram of another embodiment of a spraydrying and collection assembly.

FIG. 4 illustrates a schematic diagram of an embodiment of a spraydrying system.

FIG. 5A illustrates a top view of embodiment of a spray drying headassembly.

FIG. 5B and FIG. 5C illustrates different cross-sections of the spraydrying head assembly shown in FIG. 5A.

FIG. 6A illustrates a top perspective view of an embodiment of a dryingair filter frame.

FIG. 6B illustrates a cross-section of the drying air filter frame shownin FIG. 6A.

FIG. 6C illustrates a bottom perspective view of the drying air filterframe shown in FIG. 6A.

FIG. 7 illustrates a partial, exploded cross-sectional view of anotherembodiment of a spray drying head assembly, including the spray dryinghead shown in FIG. 5A through FIG. 5C and the filter frame assembly 360shown in FIG. 6A through FIG. 6C.

FIG. 8A illustrates a top perspective view of another embodiment of acover portion of a spray drying head assembly.

FIG. 8B illustrates a bottom perspective view of the cover portion shownin FIG. 8A.

FIG. 9A illustrates a top perspective view of another embodiment of adrying air filter frame.

FIG. 9B illustrates a bottom perspective view of the drying air filterframe shown in FIG. 9A.

FIG. 10A illustrates a bottom perspective view of an assembled spraydrying head assembly.

FIG. 10B illustrates a bottom perspective cross-sectional view of thespray drying head assembly shown in FIG. 10A.

FIG. 11 illustrates a cross-sectional view of a nozzle portion ofanother embodiment of a spray drying head assembly.

FIG. 12 illustrates a bottom view of a nozzle portion of the nozzleportion illustrated in FIG. 11.

FIG. 13 illustrates a perspective view of an embodiment of a spraydrying chamber.

FIG. 14A illustrates a front view of an embodiment of a collection bagassembly.

FIG. 14B illustrates an exploded view of an embodiment of a collectionbag assembly.

FIG. 15 illustrates a perspective view of another embodiment of acollection bag assembly.

FIG. 16 illustrates a perspective, cross-sectional view of anotherembodiment of a collection bag assembly.

FIG. 17 illustrates a perspective, cross-sectional view of yet anotherembodiment of a collection bag assembly.

FIG. 18 illustrates a perspective view of a spray-drying chamber andcollection assembly kit.

FIG. 19 illustrates a flow diagram of an embodiment of process for spraydrying a liquid.

FIG. 20 illustrates a schematic diagram of an alternate collection bagassembly pre-configured for both powder collection and subsequent fluidrehydration.

FIG. 21 illustrates a schematic diagram of another alternate collectionbag assembly with a separate chamber usable for fluid rehydration.

DETAILED DESCRIPTION

Described herein are devices and techniques for spray drying a fluid(e.g., blood plasma, whole blood, etc.) to produce a dried powder (e.g.,spray dried powder). The devices can include a spray drying assembly.The spray drying assembly can include the spray drying head attachableto a gas supplier and a liquid sample. The spray drying head can beadapted to provide an aerosolized flow of liquid sample (e.g., bloodplasma, whole blood, etc.) exposed to a drying gas (e.g., heated air,heated nitrogen, etc.). The assembly also includes a drying chamberadapted to convert the aerosolized flow of liquid sample into a driedpowder and humid air. Preferably, the assembly is disposable,collapsible, provided in a sterilized kit, and/or having simplifiedattachments allowing quick connect and disconnect from the gas andliquid sample. Separation of the powder from the humid air exiting thedrying chamber occurs within a filtered collection bag. The collectionbag can be sealed and separated from the assembly to allow for transportand storage of spray dried powder. The spray dried powder can be laterrehydrated using a rehydration fluid to produce transfusion grade plasmafor administration to a patient. In at least some embodiments, thestorage bag further includes a feature with rehydration fluid (e.g.,sterile fluid, saline, water, etc.) for rehydration of the powder into afluid.

A schematic diagram of an embodiment of a spray drying and collectionassembly is illustrated in FIG. 1. The spray drying assembly 100includes a drying chamber 102 and a collection sub assembly 104. In atleast some embodiments, the drying chamber 102 is an elongated hollowstructure having a chamber inlet 106 at one end. The chamber inlet 106is sized and shaped to accept an aerosolized liquid sample 108 (e.g.,blood plasma, whole blood, etc) and heated drying air 110. Theaerosolized liquid sample 108 and heated drying air 110 are generallydirected towards an opposing narrowed end 112 of the drying chamber 102.

The collection sub assembly 104 includes an enclosed bag 115 having anintake port 114 at one end, an exhaust port 116 at another end, and afilter 118 positioned between the intake port 114 and exhaust port 116.The filter 118 at least partially defines a collection chamber 120within the enclosed bag 115. In the illustrative embodiment, a perimeterof the filter 118 is positioned in a sealing arrangement with aninterior surface of the bag 115, such that the collection chamber 120 ispartially formed by an upper interior portion of the bag 115 and anupper surface of the filter 118.

The intake port 114 is in fluid communication with the opening at thenarrowed end 112 of the drying chamber 102. Drying air 110 interactswith the aerosolized liquid sample 108 within the drying chamber 102. Inthe illustrative embodiment, the drying chamber 102, intake port 114 andexhaust port 116 are substantially aligned along a common longitudinalaxis. The general direction of the drying air 110 and aerosolized liquidsample 108 is towards the narrowed end 112. Various parameters, such asthe temperature and pressure of the drying air 110 can be controlled tointeract favorably with the aerosolized liquid sample 108, such that asubstantially dried powder and humid air exit the narrowed end 112. Thefilter 118 is selected to trap or otherwise inhibit passage of asubstantial portion, if not all of the powder, allowing the humid air topass through. The humid air ultimately exits the bag 115 through theexhaust port, leaving a collected powder sample within the collectionchamber 120. Other variables, such as liquid sample size, particulars ofthe aerosolized liquid sample, such as droplet size and velocity,control drying time and volume of collected sample.

As illustrated in FIG. 1, the processing of the liquid sample into thedried powder is performed in a substantially linear pathway through thedrying chamber 102 and the collection sub assembly 104, therebyadvantageously reducing a collection of materials within the components(e.g., collection of materials at a bend, collection of materials at anarrow component, etc.). In some examples, the drying chamber 102 andthe collection sub assembly 104 are single unit (e.g., manufactured as asingle plastic piece) with a detachable, sealing mechanism (e.g.,self-sealing interface, valve, etc.) positioned at the intake port 114.In other examples, the drying chamber 102 and the collection subassembly 104 are collapsible along a central axis (e.g., accordioncollapse) of the drying chamber 102 and the collection sub assembly 104.In some examples, the drying chamber 102 and the collection sub assembly104 are collapsible perpendicular from the central axis (e.g., foldingcollapse) of the drying chamber 102 and the collection sub assembly 104.The collapsibility of the drying chamber 102 and the collection subassembly 104 advantageously enables the components to be stored in acompact sterile container, thereby reducing the cost for storage andshipping of the components.

A schematic diagram of another embodiment of a spray drying andcollection assembly 100′ is illustrated in FIG. 2. Similarly, theassembly 100′ includes a drying chamber 102′ in fluid communication witha collection sub assembly 104′. The drying chamber 102′ includes adrying gas port 122, a liquid sample port 124 and an aerosolizing gasport 126. Each of the liquid sample port 124 and the aerosolizing gasport 126 is in fluid communication with a nozzle 130. The nozzle 130 isconfigured to produce an aerosolized liquid sample 108 within aninterior region of the drying chamber 102′, such that the aerosolizedsample 108 is exposed to drying air 110, producing a dried powder,collectable at the collection sub assembly 104′. The nozzle 130 isconfigured to deliver the drying air 110 at a rate (e.g., 21 cubic feetper minute (cfm) at less than 2 pounds per square inch (psig), 40 cfm at5 psig, etc.) and a temperature (e.g., 112° Celsius, 105° Celsius, etc.)to minimize the moisture content within the dried plasma (e.g., lessthan 5% moisture, between 2-5% moisture, etc.) while maximizing theefficacy of the rehydrated plasma (e.g., 90% physiologically active,greater than 80% physiologically active).

Shown in FIG. 3 is a schematic diagram of yet another embodiment of aspray drying and collection assembly 100″. In a like manner, theassembly 100″ includes a drying chamber 102″ in fluid communication witha collection sub assembly 104″. Positioned in a sealing arrangement atone end of the drying chamber 102″ is a spray drying head assembly 140.The spray drying head 140 includes a drying gas port 142, a liquidsample port 144 and an aerosolizing gas port 146. Each of the liquidsample port 144 and the aerosolizing gas port 146 is in fluidcommunication with a nozzle 148. The nozzle 148, in combination withexternal sources of drying air and aerosolizing gas are likewiseconfigured to produce an aerosolized liquid sample 108 within aninterior region of the drying chamber 102″, such that the aerosolizedsample 108 is exposed to drying air 110, once again, producing a driedpowder, collectable at the collection sub assembly 104″. In operation,the drying gas port 142 can receive a high volume, low pressure, hightemperature gas (e.g., 21 cfm at less than 2 psig at 112° Celsius, 40cfm at 10 psig at 120° Celsius, etc.). The aerosolizing gas port 146 canreceive a low volume, high pressure, ambient temperature gas (e.g., 600milliliters per minute (mi/min) at 90 psig at 23° Celsius, 400 ml/min at100 psig at 21° Celsius, etc.). The high volume, low pressure, hightemperature gas provided by the drying gas port 142 can remove moisturecontent from the liquid sample 108, for example at a flow rate of about5-8 L/min. The low volume, high pressure, ambient temperature gasprovided by the aerosolizing gas port 146 can aerosolize (e.g.,suspension of the liquid droplets in the gas, formation of the driedparticles with a humidified gas, etc.) the liquid sample 108.

In particular, the assembly 100″ includes features that provide aself-contained sterile boundary to prevent contamination and inparticular bacterial contamination of any of the liquid sample and driedparticles obtained therefrom. According to general practices andguidelines, all equipment coming in contact with the blood or plasmamust have been sterilized. Beneficially, the sterile boundariesdescribed herein offer such assurances in a sterilized disposable setthat is simple, cost effective and avoids the need for sterilization(e.g., autoclaving). In the illustrative embodiment, a first filter 270is provided between the spray drying head 140 and the drying chamber102″. The first filter 270 provides a sterile boundary between thesupply of drying gas (air) and the drying chamber 102″, while allowingthe drying gas to enter the chamber 102″. A second filter 208 isprovided between the nozzle 148 and the supply of aerosolizing gas. Inthe illustrative embodiment, the second filter is an inline filterprovided along a section of tubing 208. The section of tubing 208between the second filter 208 and the nozzle 148 is preferablysterilized, as are other components of the assembly 100″, including thespray drying head 140, the drying chamber 102″ and the collection subassembly 104.″

In at least some embodiments, the entire assembly 100″ is provided as asterile disposable unit. The assembly 100″ can be manufactured andshipped in sterile condition using available medical packagingtechniques known to those skilled in the art. The assembly 100″ can beconnected to sources of drying gas and aerosolizing gas, neither ofwhich needs to be sterilized, providing a sterile boundary to preventthe transfer of bacteria into the drying chamber 102″. A liquidsuspension, such as a blood product can be connected to the liquidsample port 144 and dried through processes described herein. Driedpowder can be separated from humid air within the sterile collection subassembly 104″. The separated dried powder can be sealed within thecollection sub assembly 104″, for example, by one or more thermal welds.Subsequently, the sealed collection sub assembly 104″ containing thespray dried powder can be separated from other elements of the assembly100″, such as the drying chamber 102″ and spray drying head 140 fortransport and storage. The separated elements of the assembly 100″ canbe disposed of according to acceptable practices for disposing of suchmaterial as may be contaminated during processing.

Such provisions for maintaining sterility of the spray drying processand packaging of spray dried product are highly advantageous. Thedevices and techniques described herein, such as the example assembly100″, lessen restrictions on the spray drying process by defining asterile boundary within a disposable assembly that can be used forsterile processing and packaging of the processed product, withoutimposing sterility requirements on other portions of a spray dryingsystem external to the sterile boundary.

A schematic diagram of an embodiment of a spray drying system isillustrated in FIG. 4. The system 200 includes a spray drying assembly100″ (FIG. 3) and an aerosolizing gas source 202 in fluid communicationwith the aerosolizing gas input port 146 of the spray drying headassembly 140 through an aerosolizing gas conduit, e.g., tubing 204. Inthe illustrative embodiment, the aerosolizing gas source 202 comprises apre-charged bottle of aerosolizing gas, such as nitrogen. A valve 206and/or pressure regulator is positioned between the pre-charged bottleof gas 202 and the tubing 204 and configurable to otherwise control aflow of aerosolizing gas through the tubing 204. At least one inlinefilter 208 is provided along a length of the tubing 204, positionedbetween the gas source 202 and the aerosolizing gas input port 146. Inat least some embodiments, the filter 208 is sufficient to effectivelysterilize the aerosolizing gas, forming a sterile boundary for thatportion of tubing between the filter 208 and the gas input port 146.

A liquid sample reservoir 210 containing a liquid sample 212 is in fluidcommunication with the liquid sample port 144 through a fluid line 214.In at least some embodiments, the fluid line 214 is sterilized. Fluid istransferred from sample reservoir 210 by one or more of gravity and apump 216. In some embodiments the pump 216 is a peristaltic pump.

Drying air 110 is circulated through the drying chamber 102″ in a closedloop fashion. Humid air is separated from spray dried powder within thecollection sub assembly 104″. The humid air exits through the exhaustport 116 and is transported to a dehumidifier 220 through a first gasconduit 218. The dehumidifier 220 removes moisture from the air and themoisture exits the dehumidifier 220 through an exhaust port 221. Thedried air is transported to a blower unit 228 through a second gasconduit 226. The dried air is transported to a heater unit 224 via athird gas conduit 230. The dried air is heated to a predeterminedtemperature and transported to the drying gas port 142. Heated air isthus provided at a predetermined pressure, controllable at least in partby operation of the blower unit 228, to the spray drying chamber 102″.The dried heated air 110 is passed through a drying gas filter 270. Inat least some embodiments the drying gas filter 270 is sufficient tosterilize the dried heated air 110 (e.g., using a bacteria filter)providing a sterile boundary at an input to the spray drying chamber100″.

The heated drying air 110 interacts with the aerosolized liquid sample108 within the length of the drying chamber 102″ to produce a driedpowder and humid air at an exhaust end of the drying chamber 102″. Themixture of dried powder in the humid air is exhausted into thecollection sub assembly 104″. The filter 118 allows humid air to passthrough while otherwise preventing passage of the dried powder 119.Accordingly, the dried powder 119 accumulates within the collectionchamber 120. The humid air is exhausted and recycled within the systemrepeatedly, after drying and reheating as described above.

In at least some embodiments the system 200 includes a controller 240,such as a processor. The controller 240 is in communication with one ormore of the aerosolizing gas pressure regulator 206, the fluid pump 216,the dehumidifier 220, the heater 224 and blower unit 228. Suchcommunication can be accomplished through one or more communicationlinks 242 a, 242 b, 242 c, 242 d, 242 e (generally 242). These links 242can be wired or wireless. The controller 240 can be configured toinstruct the one or more devices 202, 216, 220, 224, 228 under itscontrol as may be necessary to control the spray drying process.Alternatively or in addition, the controller 240 can be configured toreceive feedback from one or more of the devices 202, 216, 220, 224,228, as may be advantageous to control the spray drying process.

In at least some embodiments one or more sensors are provided atstrategic locations throughout the system. For example, temperaturesensors such as thermocouples 266 a, 266 b (generally 266) can beprovided at the drying gas input port 142 and at the outlet port 116 ofthe collection sub assembly. Other sensors may include flow meters,pressure sensors, and/or light sensors. Such sensors can be incommunication with the controller 240, for example by way of acommunication link or conductive lead 267, providing feedback usable bythe processor to control or otherwise improve the spray drying process.

In at least some embodiments, the sample reservoir 210 is configured toprovide a standard unit of a blood product, such as a typical bloodsupply bag accommodating one unit of whole blood, which is approximately450 ml, or about 0.951 pints. In some embodiments, the reservoir 210 caninclude one or more other liquid blood products, such as plasma, thefluid portion of one unit of human blood that has been centrifuged andseparated. For such embodiments configured for single unit processing,the collection sub assembly 104″ is also sized to accommodate theresulting spray dried product obtained from processing the single unitof blood product. As the liquid portion of the blood product has beenremoved by the spray drying process, a storage volume of the collectionsub assembly 104″ can be smaller than the volume of the sample reservoir210. In at least some embodiments, however, the storage volume of thecollection sub assembly 104″ can be as large as or even larger than thevolume of the sample reservoir 210. For example, the storage volume ofthe collection sub assembly 104″ can include sufficient volume toaccommodate later rehydration of the spray dried blood product asdescribed in more detail below.

When used for single unit processing, the entire disposable assembly100″ is preferably replaced after processing a single unit of bloodproduct. This practice maintains sterility and prevents crosscontamination as might otherwise occur if the same disposable assembly100″ were to be used for processing multiple sample units of bloodproduct. After processing, the collection sub assembly 104″ can beremoved from the system 200 and separated from other portions of thedisposable assembly 100″, such as the drying chamber 102″. The spraydried blood product thus obtained can be safely stored within thecollection sub assembly 104″ for much longer duration than otherwisewould be possible. The remaining portions of the disposable assembly100″ can then be disposed of.

Alternatively or in addition, the sample reservoir 210 can be configuredto provide more than a standard unit of blood product. Such larger unitsare typically the result of pooling together multiple units of bloodproduct. Such pooling can be accomplished, for example, by providing asingle larger sample reservoir 210. For example, in a pooling scenarioof 10 units of blood product (e.g., 450 ml each), the single pooledreservoir 210 would provide sufficient volume to accommodate at leastabout 4.5 L of blood product. It is also understood that in someembodiments, pooling can be accomplished by otherwise combining multiplestandard units of blood product prior to injection into the dryingchamber 102″. For example, such pooling can be accomplished by includingmultiple sample reservoirs 210 in a parallel arrangement, with tubingsegments from each of the individual sample reservoirs 210 combined(e.g., a manifold) prior to reaching the peristaltic pump 216. In thismanner, the single pump 216 can pump the contents of all of the multipleparallel sample reservoirs 210 in a controlled flow suitable for spraydrying processing. In yet another scenario, pooling can be accomplishedin a serial process, in which single unit reservoirs 210 aresequentially coupled to the pump 216, their contents spray dried andcollected in a single collection sub assembly 104″ as described herein.

In order to accommodate a larger volume of spray dried blood product,the collection sub assembly 104″ can be larger. For example, acollection sub assembly 104″ configured to accommodate the 10 unitpooling example, whether obtained by a parallel or serial, sequentialarrangement, can be sized approximately 10 times larger than wouldotherwise be preferable for processing of a single unite. It is worthnoting here that the spray drying process is a continuous flow process.As such, there are no particular size constraints imposed on otherportions of the system 200, such as the drying chamber 102″. Thus,whether the system 200 is configured to process single units or pooledunits, a drying chamber 102″ of a common size and shape can be used toaccommodate both.

A top view of an embodiment of a spray drying head assembly isillustrated in FIG. 5A. The spray drying head 300 includes a dryingchamber cover 302 in outer perimeter 304. In the illustrative embodimentthe outer perimeter 304 is circular. The center region of the dryingchamber cover 302 includes a sterile liquid sample port 306 and asterile aerosolizing gas port 308. A drying gas conduit 310 extendsbetween an attachment fixture 320 and a drying gas manifold 312. In theillustrative embodiment the drying gas manifold 312 is helical extendingaround the central region of the drying chamber cover 302. Thehelically, centralized drying gas manifold 312 enables the drying gas tobe gradually released into drying chamber as the drying gas moves aroundthe circular drying gas manifold 312 while still maintaining asufficient positive pressure with respect to the drying chamber. Theattachment fixture 320 includes a drying gas port 322 and anaerosolizing gas port 326. The drying gas port 322 is circular includinga peripheral sealing surface 324 adapted for mating with a complementarysealing surface. Likewise, the aerosolizing gas port 326 is circularalso including a peripheral sealing surface 328. An attachment flange330 extends along either side of the center line of the drying gasconduit 310.

Illustrated in FIG. 5B, is a first cross-section B-B of the spray dryinghead assembly 300 shown in FIG. 5A. The cross-section B-B revealshelical nature of the drying gas manifold 312. Drying gas enters fromthe conduit 310 and spirals around the central region. The height of themanifold 312 decreases as the volume of drying gas decreases,maintaining a substantially constant pressure within the manifold 312. Avolume of the drying gas decreases as the gas, exposed to the filter inthe manifold 312, passes through a drying gas filter 370.

A second cross-section of the spray drying head assembly shown in FIG.5A, is illustrated in FIG. 5C, taken along a plane bisecting the dryingair conduit 310 and including the aerosolizing gas input port 326.Drying gas received from a drying gas source through the drying gas port322, passes through the conduit 310 as indicated by the arrow and intothe manifold 312. The manifold 312 allows the drying gas to spreadthroughout an open volume adjacent to the drying gas filter 370.Pressure provided by an applied flow of drying gas forces drying gasfrom the manifold 312 through the drying gas filter 370 as indicated bythe vertical arrows. There is no particular requirement that either thedrying gas source (not shown), or the drying gas port 322, conduit 310or manifold 312 be sterile. The drying gas filter 370 can be asterilizing filter (e.g., bacteria filter) provided between the manifold312 and an interior volume of a spray drying chamber adjacent to thefilter 370. Such a sterilizing drying gas filter 370 creates a sterileboundary for the drying gas, such that drying gas having passed throughthe filter 370 is sterile as it passes into the spray drying chamber.

Referring again to FIG. 5B, a diameter of the drying chamber cover 302measured from diametrically opposing portions of outer peripheralattachment surface 340 is D₁. A diameter of that portion of the manifold312 open to the drying gas filter 370 is D₂. Also shown in cross-sectionis a portion of an inner nozzle 307, including a central bore 306. Thewidth of the nozzle region is D₃, such that the region exposed to anannular filter (e.g., filter 270, FIG. 4) is radially measured from D₃/2to D₂/2 (an annular width, W).

Illustrated in the cross section is an aerosolizing gas conduit 351extending between an aerosolizing gas fitting 352 and the sterileaerosolizing gas port 308. In at least some embodiments, theaerosolizing gas fitting 352 can be an integral feature of theattachment fixture 320, as shown. Aerosolizing gas received from a gassource through the aerosolizing gas port 326, passes through an internallumen of the attachment fixture 320, exiting at the aerosolizing gasfitting 352. There is no particular requirement that either theaerosolizing gas source, or the aerosolizing gas fitting 352 be sterile.The aerosolizing gas conduit 351 includes a sterilizing filter 353(e.g., bacteria filter) provided between the aerosolizing gas fitting352 and the sterile aerosolizing gas port 308. The sterilizing filtercreates a sterile boundary for the aerosolizing gas, such thataerosolizing gas having passed through the filter 353 is sterile as itpasses through the aerosolizing gas port 308.

A top perspective view of an embodiment of a drying air filter frameassembly 360 is illustrated in FIG. 6A. The filter frame assembly 360includes an annular filter support frame 362, defined between a centralhub 364 and an outer circumferential rim 366. The filter support frame362 includes multiple ribs or spokes 368, extending radially between thecentral hub 364 and the outer rim 366. Open areas 371 are definedbetween adjacent spokes 368, an outer perimeter of the central hub 364and the rim 366. The filter support frame 362 provides substantialsupport to an annular drying gas filter 370 (FIG. 6B), for example,holding the drying gas filter 370 in place under anticipated pressuresduring spray drying operation. Preferably, the filter support frame 362provides such support, while minimally impeding or otherwise blockingthe filter surface. In the illustrative example, it can be seen that thearea 371 defined between spokes 368 is substantially greater than thearea otherwise blocked by the spokes 368.

A cross-section of the drying air filter frame assembly 360 includingthe annular drying gas filter 370 is illustrated in FIG. 6B.Dimensionally, the diameter of the outer rim is represented by D₂′,whereas, the radial extent of the annular region between the central hub364 and the rim is represented by W′. An example of an annular filter isshown positioned against the spokes.

The central hub includes a raised cylindrical section 378, extending fora height above a plane containing the spokes. The raised cylindricalsection 378 includes an annular, top-facing abutting surface, extendingradially inward. A central cavity 372 is defined along an inner extentof the abutting surface. The central cavity extends axially, toward theplane containing the spokes. A bottom end of the central cavityterminates in a conical surface 376, defining a central orifice 374. Abottom perspective view of the drying air filter frame assembly isillustrated in FIG. 6C. The central orifice is shown in centralalignment with a central axis.

A partial, exploded cross-sectional view is illustrated in FIG. 7 ofanother embodiment of a spray drying head assembly, including the spraydrying head assembly 300 illustrated in FIG. 5A through FIG. 5C and thefilter frame assembly 360 illustrated in FIG. 6A through FIG. 6C. Alsoshown in cross section is the drying gas filter 370. The spray dryinghead assembly 300 defines an aerosolizing gas manifold 398 open to abottom side of the assembly 300. The aerosolizing gas manifold 398includes an annular recess inscribed within the helix of the drying gasmanifold 312. The two manifolds 312, 398 are separated by a wall toallow each to operate at independent pressures without interfering withthe other (e.g., the manifold 312 operating at high pressure and themanifold 398 operating at low pressure, the manifold 312 operating athigh pressure and the manifold 398 operating at low pressure).

A nozzle 375 extends into a central region of the aerosolizing gasmanifold 398. The nozzle 375 includes a central bore 377 extendingthrough the nozzle 375 and open at both ends, forming a channelpenetrating the spray drying head assembly 300 from top to bottom. Inassembly, the filter frame assembly 360 is centrally aligned with thespray drying head assembly 300 along a central axis containing thecentral bore 377 and a centerline of the nozzle cap 376. The nozzle capincludes an orifice 374 that is also aligned with the central bore 377of the nozzle 375.

When assembled, the abutting surface 378 of the filter frame assembly360 extends into the aerosolizing gas manifold 398 of the spray dryinghead assembly. A drying air filter (e.g., filter 270, FIG. 4) is heldinto place, firmly against a bottom surface of the spray drying headassembly 300, such that the open areas 371 between spokes 368 align withan at least partially annular opening to the drying air conduit 312,allowing drying air forced through the conduit 312 to exit the spraydrying head assembly 300 through the drying air filter 270.

When assembled, a generally narrow opening remains between an outersurface of the nozzle 375 and the open cavity 372 of the central hub364. The narrow opening allows aerosolizing gas to pressurize the narrowarea, exiting the spray drying head assembly 300 through the nozzle caporifice 374. In at least some embodiments the nozzle cap orifice 374 canbe partially blocked by a distal tip of the nozzle 375, presenting anannular opening for exit of the aerosolizing gas.

The example embodiment also includes a Luer fitting cannula 390 forconveying a liquid sample through the spray drying head assembly 300.The Luer fitting cannula 390 includes a precision fluid channel 392provided by a cannula 393 defining a central bore. The central bore 392extends from the Luer fitting 396 at one end, to a fluid channel orifice394 at an opposite end. In the example embodiment, the central bore 377of the nozzle 375 is suitably dimensioned to accept the cannula 393,forming a fluid-tight seal therebetween.

A top perspective view of another embodiment of a cover portion of aspray drying head assembly is illustrated in FIG. 8A. The spray dryinghead 400 includes a drying chamber cover 402 defining an outer perimeter404. In the illustrative embodiment the outer perimeter 404 is circular.The center region of the drying chamber cover 402 includes a sterileaerosolizing gas nipple 414. A drying gas conduit 408 extends between anattachment fixture 412 and a drying gas manifold 406. In theillustrative embodiment the drying gas manifold 406 is annular extendingaround a depression 415 of the drying chamber cover 402. The attachmentfixture 412 includes a drying gas port 413 a and an aerosolizing gasport 413 b. An aerosolizing gas conduit 416 extends between theaerosolizing gas port 413 b and aerosolizing gas nipple 414. In at leastsome embodiments, the aerosolizing gas port 413 b can be an integralfeature of the attachment fixture 412, as shown. Aerosolizing gasreceived from a gas source through the aerosolizing gas port 413 b,passes through an internal lumen of the attachment fixture 412, exitinginto the aerosolizing gas conduit 416 The aerosolizing gas conduit 416includes a sterilizing filter 417 (e.g., bacteria filter) providedbetween the aerosolizing gas port 413 b and the aerosolizing gas nipple414. The sterilizing filter 417 creates a sterile boundary for theaerosolizing gas, such that aerosolizing gas having passed through thefilter 417 is sterile as it passes through the aerosolizing gas nipple414.

A bottom perspective view of the cover portion 402 shown in FIG. 8A, isillustrated in FIG. 8B. An underside of the central depression 415extends into a central region of the drying air manifold 406, such thatan annular opening is formed between the central depression 415 and anouter peripheral portion of an underside of the cover 402. A drying gasinlet port 419 opens from the drying air conduit to the drying airmanifold 406 allowing for the passage of drying air from an externalsource to the manifold 406.

Extending further from a central region of the central depression is aninner, nozzle 426. The nozzle 426 includes a sidewall, or collar 423 anda fluid channel aperture 428. Formed along a base portion of the collar423 is a shoulder region of the central depression 415. The shoulderregion includes an outer, circumferential ridge 422 extending above anannular well 420. An aerosolizing gas port 424 penetrates the annularwell 420, allowing for the passage of aerosolizing gas through thenipple 414 to penetrate the cover 402.

A top perspective view of another embodiment of a drying air filterframe assembly 450 is illustrated in FIG. 9A. The filter frame assembly450 includes an annular filter support frame, defined between a centralhub 452 and an outer circumferential outer rim 454. The filter supportframe includes multiple ribs or spokes 455 extending radially betweenthe central hub 452 and the outer rim 454. Open areas 456 are definedbetween adjacent spokes 454, an outer perimeter of the central hub 452and the rim 454. The filter support frame provides substantial supportto an annular filter (not shown), for example, holding the filter inplace under anticipated pressures during spray drying operation.Preferably, the filter support frame provides such support, whileminimally impeding or otherwise blocking the filter surface. In theillustrative example, it can be seen that the area 456 defined betweenspokes 455 is substantially greater than the area otherwise blocked bythe spokes 455.

An annular abutting surface 460 of the hub 452 is substantially alignedin a common plane with at least one of the spokes 455 and the outer rim454, although it is understood that one or more may be offset by aslight measure, for example, a filter thickness. Also defined within acentral region of the hub 452 is an open cavity 462. The cavity 462extends away from the alignment plane, in a direction toward filtereddrying air flow (unfiltered drying air enters from above the topportion). As can be seen in FIG. 9B, the depression 462 defines a nozzlecap 470, defining a central orifice 471. The central hub 452 alsoincludes a cylindrical shroud 468 extending away from the abuttingsurface 460, in a direction of filtered drying air flow.

An annular wall section 464 extends between the outer rim 454 and aninner rim 456. The inner rim 456 is diametrically smaller than the outerrim 454. Additionally, the inner rim 456 resides in a plane parallel tothe alignment plane above, but offset in a dimension extending in thedirection of filtered drying air flow. In the illustrative example, anopen end of the cylindrical shroud 468 and the inner rim 456 residesubstantially within a common plane. In operation, forced drying airpasses through a relatively larger filter area defined between the outerrim 454 and the central hub 452, into a plenum formed by the annularwall section 464, and exiting the filter frame assembly 450 through areduced open area defined between the inner rim and a centrally disposedcylindrical shroud 468. The reduction in cross-sectional area presentedto the heated drying air results in an increase in velocity.

A bottom perspective view of an assembled spray drying head assembly 480is illustrated in FIG. 10A. An example annular disk filter 482 isvisible viewed from an underside of the assembly, between an openingformed between the inner rim 456 and the cylindrical shroud 468.

A bottom perspective cross-sectional view of the spray drying headassembly shown in FIG. 10A, is illustrated in FIG. 10B. An aerosolizinggas manifold 484 is formed between the abutting surface 460 of the hub452 and the annular well 420. The outer, circumferential ridge 422provides a stop to the abutting surface 460, allowing for a measuredopen area to accommodate the aerosolizing gas flow. The assembly 480also includes a precision fluid channel 490 for transporting fluidthrough the spray drying head assembly 400 and into the spray dryingchamber. In at least some embodiments, the precision fluid channel 490can be provided by a commodity cannula terminating in a standard fluidfitting 492, such as a Luer lock.

A cross-sectional view of a nozzle portion of another embodiment of aspray drying head assembly is illustrated in FIG. 11. An inner nozzle426′ is disposed adjacent to a nozzle cap 470′. The cannula 490′ definesa precision fluid channel, terminating in a precision fluid channelorifice 491′. The cannula 490′ extends through a central bore of thenozzle 426′, such that a tip of the cannula 490′ extends for arelatively short distance beyond a termination of a central bore. Thecentral bore is aligned with central orifice 471′ of the nozzle cap470′, such that the extending portion of the cannula 490′ extends atleast into the aperture 471′. In at least some embodiments, an annularopening 479′ is defined between an outer peripheral edge of theextending portion of the cannula 490′ and the nozzle cap orifice 471′.

Aerosolizing gas enters through an aerosolizing gas inlet port 414′ andcirculates within an aerosolizing gas manifold 484′. The manifold 484′is adjacent to an exposed narrow region 477′ defined between opposingsurfaces of the nozzle 426′ and the nozzle cap 470′, such thatpressurized aerosolizing gas is forced through the narrow region 477′,exiting the assembly through the annular opening 479′. The relativespacing defining the narrow region 477′ can be controlled according toan interface of an abutting surface 483′ of the nozzle cap 470′ and anopposing surface of the nozzle 426′.

Advantageously, the exiting air aerosolizes fluid exiting the precisionfluid channel orifice 491′. Relative flow rates of the liquid sample ascontrolled by one or more of a sample fluid pump rate and diameter ofthe precision fluid cannula 490′, in combination with one or more ofaerosolizing gas pressure (flow rate), the dimensions of the narrowregion 477′ and the annular orifice 479′ interact to create and maintainan aerosolized plume of the sample fluid extending away from theprecision fluid channel orifice 491′.

A bottom view of a nozzle portion of the nozzle portion illustrated inFIG. 11, is illustrated in FIG. 12. A surface of the nozzle 428″ exposedto the aerosolizing gas injected at the aerosolizing gas port 424″includes one or more surface features adapted to induce a preferentialmovement of the aerosolizing gas. For example, the one or more suchfeatures can include ridges 426″ or troughs 427″, as shown. The ridges426″ or troughs 427″ can be arranged in a spiral orientation to induce aturbulence for aerosolizing gas passing by. The turbulence, in turn, canbe used to establish a relatively circular air flow about the nozzle428″. In some embodiments, no such surface features are necessary.

A perspective view of an embodiment of a spray drying chamber 500 isillustrated in FIG. 13. The spray drying chamber 500 defines anelongated drying volume, extending along a central longitudinal axis. Inthe exemplary embodiment, the drying chamber 500 includes a firstcolumnar wall section 506 having a relatively wide opening at one end.An opposite end of the columnar walls section 506 couples to a narrowcolumnar section 510 through a shoulder wall section 508. The narrowcolumnar section 510 has a relatively narrow opening disposed at an endopposite the relative wide opening, the two openings being aligned alongthe central axis. For illustration purposes, a diameter of the firstcolumnar section is shown as D₁ (e.g., 8 inches, 5 inches, etc.) and adiameter of the narrow columnar section 510 is shown as D₂ (e.g., 1inch, 2 inches), with D₂<D₁. An axial length of the drying chamber 500is shown as L₁ (e.g., 12 inches long, 20 inches long, etc.). An axiallength of the first columnar wall section 506 is shown as L₂ (e.g., 14inches, 22 inches, etc.). In the illustrative embodiment, the length ofthe shoulder wall section 508 and narrow wall section 510 (i.e., L₁-L₂)is substantially less than the length of the columnar wall section 506.Thus, most of the interior region of the drying chamber 500 is availablefor interaction of an aerosolized plume of sample liquid with heateddrying gas.

In operation, a plume of aerosolized sample liquid is introduced intothe relatively wide open end. Heated drying air is also introduced intothe relatively wide open end, such that the heated drying air comes intoextended contact with the plume of aerosolized sample liquid. As aconsequence of such interaction, moisture is removed from the plume ofaerosolized sample liquid, while velocities of one or both of theaerosolized sample liquid and heated drying gas moves humid drying airand dried powder toward the relatively narrow column section 510. Aconstriction resulting from the shoulder section 508 can maintain adesired amount of back pressure within the drying chamber 500.

The drying chamber 500 can be configured as shown, such that a flow ofaerosolized liquid and drying air entering the chamber 500 is directedalong a longitudinal axis. Likewise, channeling of dried powder andhumid air exiting the chamber 500 is also directed along the samelongitudinal axis. Maintaining such a linear flow without any bends,prevents unwanted collection of dried powder as might otherwise occur.Preferably all of the spray dried powder is transported from the chamber500 to a separation and collection device. In at least some embodimentsfurther prevention of unwanted collection of dried powder can beachieved by arranging the longitudinal axis vertically. The aerosolizedliquid sample and drying air enter the drying chamber 500 from an upperportion and separation and collection occurs at a lower portion. In suchconfigurations, gravity promotes the transfer of spray dried powderdownward, along the longitudinal axis and towards the separation andcollection chamber.

One or more of the drying chamber components, including the columnarwall section 506, the shoulder wall section 508 and the relativelynarrow wall section 510 can be constructed from a rigid material, suchas glasses, ceramics, metals, including alloys (e.g., stainless steel),and plastics. Alternatively or in addition, one or more of thecomponents of the drying chamber can be semi-rigid, for example, beingfashioned from a semi-rigid plastic. Such components can be fabricatedin such a manner to allow for collapse of at least a portion of thedrying chamber 500. For example, at least a portion of at least thecolumnar wall section 506 can be fabricated as a circumferentialaccordion arrangement to allow for selective collapse, reducing overalllength L₁, substantially, as may be advantageous for packaging andstorage.

Alternatively or in addition, one or more of the components of thedrying chamber can be at least one of flexible, pliable, bendable,collapsible, and floppy. In such applications, the wall sections areprepared as relatively thin members. For example, one or more of thecomponents can be fabricated from the same or similar material ascommonly used in blood storage bags, such as a polyvinyl chloride (PVC)film. In at least some embodiments, one or more elements of the dryingchamber 500 are translucent or transparent, allowing for visualinspection or machine interrogation (e.g., optical interrogation) as tothe status of the process.

The entire drying chamber 500 can be fabricated as a single unit, forexample, being molded, extruded or otherwise shaped as described above,without seams. Alternatively, one or more sections of the drying chamber500 can be fabricated as different pieces, joinable along seams. Onesuch example includes a first and second wall columnar wall sections 502a, 502 b, cut to a suitable pattern and joined along common seams 504 a.Such joining can be accomplished by one or more of mechanical attachment(e.g., clamps or fasteners), welding and bonding.

A front view of an embodiment of a collection bag assembly 600 isillustrated in FIG. 14A. The collection bag assembly 600 includes anouter bag 602 including an inlet port 608 and an exhaust port 610. Inthe illustrative example, the outer bag 602 is formed from threecomponents: a first side wall 604 a, a second side wall (not shown), anda top wall section 604 c. The side walls can be joined together alongseams to form an enclosed, fluid-tight volume, but for the inlet andexhaust ports 608, 610.

A filter 620 is suspended within the outer bag 602, dividing the outerbag into two chambers: a collection chamber 626 and an outer chamber628. The collection chamber is open to the inlet port 608; whereas, theouter chamber is open to the exhaust port 610. In at least someembodiments, the collection bag assembly 600 includes a filter support622. The filter support 622 can be made from semi-rigid material, suchas a plastic, PVC, and the like. In the illustrative example, the filtersupport 622 is located at an interface between the filter 620 and theouter bag 602. The filter 620 can be planar, for example, extendingacross an interior portion of the outer bag 602. Alternatively, thefilter 620 can be non-planar, for example, forming a pouch shape withinthe outer bag 602.

In operation, a mixture of humid air and spray dried material (i.e.,powder) enters the collection chamber 626 via the inlet port 608. Thefilter is selected to block passage of the spray dried material, whileallowing humid air to pass through. An example filter is 0.22 micronhydrophobic filter. Such filters can be made from suitable materials,such as ePTFE or PVDF. Example filters include a 0.22 micron PVDFDURAPORE® commercially available from Millipore of Billerica, Mass. andePTFE 0.22 micron GORE® membrane filters, commercially available fromW.L. Gore & Associates.

In at least some embodiments, the collection bag 600 is configured withone or more additional features. Examples of such features include oneor more ports for accessing the collection chamber. In the illustrativeembodiment two such ports, generally known as “spike” ports 614 areshown. Alternatively or in addition, other interfaces, such as a tubing612 can be provided. Once again, the tubing 612 is in fluidcommunication with the collection chamber. The collection bag assembly600 may also contain a mounting flange 616, for example, to hang the bagfrom an IV pole and a label 624 suitable for identifying informationrelated to the collected sample (e.g., sample identification, date).

An exploded view of an embodiment of a collection bag assembly 600 isillustrated in FIG. 14B. In particular, the illustrated embodimentincludes an exhaust extension conduit 630 attachable at one end to theexhaust port 610. An opposite end of the exhaust extension conduit 630can be terminated with an exhaust port cap 632. In at least someembodiments, the exhaust port cap 632 is provided as a “spike” styleport. It should be noted that any spike style port at the exhaust portcap 532, although similar in application to traditional Spike ports,will generally be much larger due to the relative dimensions between theexhaust port (relatively large) and any of the other ports (relativelysmall).

A perspective view of another embodiment of a collection bag assembly600′ is illustrated in FIG. 15. The collection bag assembly 600′includes an outer bag 602′ having an inlet port 608′ and an exhaust port610′. A filter 620′ is suspended within the outer bag 602′, once again,dividing the outer bag into two chambers: a collection chamber 626′ andan outer chamber 628′. The collection chamber 626′ is open to the inletport 608′; whereas, the outer chamber 628′ is open to the exhaust port610′.

In at least some embodiments, the collection bag assembly 600′ includesa filter support 622′. In the illustrative example, the filter support622′ is located at a lower portion of the outer bag 602′. The filter620′ can be planar, for example, extending across an interior portion ofthe outer bag 602′. Alternatively, the filter 620′ can be non-planar,for example, forming an inverted pouch shape, extending upward withinthe outer bag 602′, away from the filter support 622′ in a directiontowards the inlet port 608′. It is envisioned that in at least someembodiments, the filter 620′ is adapted to substantially remain in theinverted pouch position during operation (e.g., in the presence ofpressurized drying air directed toward the exhaust port 610′. In suchembodiments, it is understood that one or more additional filtersupports can be provided to assist in maintaining such a shape.

A perspective, cross-sectional view of another embodiment of acollection bag assembly is illustrated in FIG. 16. The collection bagassembly 600″ includes an outer bag 602″ having an inlet port 608″ andan exhaust port 610″. A filter 620″ is suspended within the outer bag602″, once again, dividing the outer bag into two chambers: a collectionchamber 626″ and an outer chamber 628″. The collection chamber 626″ isopen to the inlet port 608″; whereas, the outer chamber 628″ is open tothe exhaust port 610″.

In the illustrative embodiment, the filter 620″ substantially definesthe collection chamber 626″. This can be accomplished, as shown, withthe filter 620″ forming an inner “bag” disposed within the outer bag602″. The inner filter 620″ can be suspended from the top portion of theouter bag 602″, for example, being attached to an inner portion of theouter bag 602″ along a top seam 632″. Alternatively or in addition, theinner filter 620″ can be attached to other inner portions of the outerbag 620″, for example, along one or more side seams 630″.

Advantageously, attachments retain the filter 620″ in place, forming thecollection chamber 626″. Pressure from the drying gas and powderentering through the inlet port 608″ naturally expand the collectionchamber 626″, the filter retaining dried powder within the collectionchamber 626″, while allowing humid drying gas to enter the outer chamber628″. In at least some embodiments, the outer bag is dimensioned to besufficiently larger than the collection chamber 626″ to allow humiddrying air to expand the outer chamber 628″, effectively urging theouter bag 602″ away from the filter surface, to inhibit blocking of thefilter 620″ by any inner surface of the outer bag 602″. Humid drying gasis exhausted through the exhaust port; however, a dimensionalrestriction of the exhaust port 610″ provides a backpressure promotingexpansion of the outer bag 602″.

A perspective, cross-sectional view of yet another embodiment of acollection bag assembly is illustrated in FIG. 17. The collection bagassembly 600′″ includes an outer bag 602′″ having an inlet port (notshown) and an exhaust port 610′″. A filter 620′″ is suspended within theouter bag 602′″ dividing the outer bag 602′″ into two chambers: acollection chamber 626′″ and an outer chamber 628′″. The collectionchamber 626′″ is open to the inlet port 608′″; whereas, the outerchamber 628′″ is open to the exhaust port 610′″.

In the illustrative embodiment, the filter 620″ substantially definesthe collection chamber 626′″. This can be accomplished, as shown, withthe filter 620′″ forming an inner “bag” disposed within the outer bag602′″. The inner filter 620′″ can be suspended from the top portion ofthe outer bag 602″, for example, being attached to an inner portion ofthe outer bag 602″ along conduits extending from the exhaust port 610′″and one or more other fluid interfaces. The illustrative embodiment canbe distinguished from the previous example at least in that the filter620′″ need not be attached along any seams of the outer bag 602′″. Forexample, the filter 620′″ can be formed as a stand-alone bag,essentially defining the entire inner chamber 626′″. Operation of such acollection bag assembly 600′″ would be much the same as the previousembodiment illustrated in FIG. 16. In some examples, the inner filter620′″ does not extend the entire length of the outer bag 602′″ to reduceand/or to prevent clogging of the exhaust port 610′″.

Upon completion of processing a liquid sample, any spray dried powderseparated by any of the filtering techniques described herein, remainswithin a collection chamber of the collection bag assembly. Theaerosolizing gas supply can be disabled or otherwise removed and anyfluid pumping of the liquid sample can cease. The drying air supply canalso be disabled in a similar manner. In at least some embodiments, thespray drying process is accomplished in a sterile volume at leastdefined between the liquid sample reservoir, input to the spray dryinghead, and the exhaust port. Thus, the spray drying process takes placein a sterile environment of the spray drying chamber, and the liquidsample is exposed to sterilized aerosolizing gas and sterilized dryingair gas. The collection bag assembly can be sealed by any suitabletechnique to secure a collected powder sample within the collection bag,while maintaining sterility of the collected sample. For example, athermal weld can be applied to each of the inlet port and outlet port ofany of the collection bag assemblies described herein. The thermal weldsubstantially seals off either respective port from the externalenvironment. Such a sealing process can be followed by a separationprocess, for example, whereby the intake port is separated from thespray drying chamber and the exhaust port is separated from any gasconduit coupled thereto.

A perspective view of a spray-drying and collection assembly kit 700 isillustrated in FIG. 18. The kit 700 includes an in-line drying chamber702, a collection bag assembly 704, a spray drying head assembly 706,and an elongated feed tube 708, terminated in one end with a male Luerlock fitting and sealed at the other end. The collection bag assembly704 includes an intake sealing point 723 and an exhaust sealing point722. In at least some embodiments, the collection bag assembly 704 ispre-attached to a length of sterile tubing 716. An end of thetransfusion tube 716, opposite the collection bag assembly 704, can bepre-sealed, for example, by a thermal weld. When pre-sterilized, thepre-sealed end preserves sterility of the collection chamber which canotherwise be open to the attached length of tubing 716. In suchembodiments, the tubing can represent transfusion-type tubing that canbe accessed or otherwise joined to similar tubing and/or equipment asused in transfusing a rehydrated powder.

It is envisioned that such a collection assembly kit 700 can be providedas a disposable item in the overall context of the spray drying process.In at least some embodiments, such a disposable kit 700 ispre-sterilized and packaged in a sterilized container (e.g., a blisterpackage, sealed from the environment, for example by a durable barrier,such as TYVEK®, a registered trademark of E.I. du Pont de Nemours andCompany). The sterilized container can be opened in a controlledprocessing environment, and the components of the spray-drying andcollection assembly interconnected to a liquid sample, gas supplies andother system components in such a manner as to preserve sterility of theprocessing and collection volumes.

A flow diagram of an embodiment of process 750 for spray drying a liquidis illustrated in FIG. 19. The process includes aerosolizing a liquidsample at 755, drying the aerosolized liquid sample at 760, so as toproduce a powder and humid air, and a combined separation of the humiddrying air from the powder and collection of the powder at 765

Beneficially, a spray dried powder collected in the collection bagassembly can be rehydrated with a suitable fluid, such as a salinesolution. Rehydration can be accomplished outside of the collection bagassembly by transferring the collected powder to a rehydration vessel.Preferably, however, at least with respect to blood processingapplications, rehydration can be accomplished within the collection bagassembly. In such applications, a measured volume of rehydration fluidis added to the collection bag, for example, through an available port,such as one of the “spike” ports in the illustrated embodiments.Agitation can be applied to the powder-fluid mixture to achieve adesired rehydration. In at least some embodiments, such rehydrated fluidcan be used in a treatment of a patient, for example, by transfusion.Thus, in at least some embodiments, such a rehydrated fluid can betransferred directly from the collection bag assembly to a patient. Suchtransfer can be accomplished, for example, by the available closed endsterile tubing (i.e., transfusion tube) and/or one or more availableports, such as the “spike” ports of the illustrative embodiments.

It is understood that in at least some embodiments, a collection bagassembly can be pre-configured for both powder collection and subsequentfluid rehydration. For example, the collection bag assembly can includea rehydration fluid chamber. In some embodiments, the reconstitutionfluid chamber can be pre-charged with a suitable measure ofreconstitution fluid. An embodiment of such an assembly is schematicallyrepresented in FIG. 20. The collection bag assembly 800 includes anouter bag 802 having an inlet port 808 and an exhaust port 810. Afiltered collection chamber 826 is disposed within the outer bag 802. Anouter chamber 828 is provided in an area between the filtered collectionchamber 826 and the exhaust port 810. Sealing regions 811, 811′ areillustrated by dashed lines on each of the intake and exhaust ports 808,810.

The collection bag assembly 800 also includes a rehydration fluidreservoir 830. The rehydration fluid reservoir 830 can be provided inselective fluid communication with the collection chamber 826, forexample, by way of a controllable flow valve 832. The valve 832 can be afrangible device, adapted to maintain isolation between the pre-chargedrehydration fluid reservoir 830 and a collected powder 827, until suchtime as rehydration is desired. Such rehydration can be accomplished,for example, by manipulating the collection bag assembly 800, forexample, by one or more of vigorous shaking, bending, stretching andapplication of pressure, for example, to fluid in the pre-chargedrehydration chamber 830. Rehydrated fluid can be accessed by atransfusion port 840.

Another embodiment rehydration is schematically represented in FIG. 21.A collection bag assembly 850 includes an outer bag 852 having an inletport 858 and an exhaust port 860. A filtered collection chamber 866 isdisposed within the outer bag 852. An outer chamber 868 is provided inan area between the filtered collection chamber 866 and the exhaust port860. A separate rehydration fluid reservoir 870 is provided. Therehydration fluid reservoir 870 can be connected via a flowline 872 toprovide selective fluid communication with the collection chamber 866.For example, by way of one or more controllable flow valves 874′, 874″(generally 874). One or more of the valves 874 can be a frangibledevice, adapted to maintain isolation between the pre-chargedrehydration fluid reservoir 870 and a collected powder 867, until suchtime as rehydration is desired. Such rehydration can be accomplished,for example, by manipulating the fluid reservoir 870, for example, byapplication of pressure, for example, to fluid in the pre-chargedrehydration chamber 870. Rehydrated fluid can be accessed by atransfusion port 880.

Generally, the devices and techniques described herein are scalable. Forexample, and without limitation, any of the devices and techniquesdescribed herein can be applied to single units of blood. It is alsoenvisioned that any of the devices and techniques described herein canalso be applied to liquid samples larger than typical blood units. Forexample, such larger samples can be obtained from pooled multi-unitblood samples. More generally, there is no apparent limit to thescalability of the devices and techniques described herein. Where anydimensions have been included or suggested, it is by way of example onlyand intended without limitation. Thus, any of the reservoirs andcollection chambers described herein and equivalents thereto can besized and shaped to accommodate processing of single units (e.g., 450 mlliquid blood product), pooled units (e.g., multiples of the standardunits), or any suitable size and shape as may be necessary toaccommodate liquid blood products and spray dried blood productsprocessed by the system.

Although the illustrative examples describe herein are generallydirected to the processing of human blood products, such as plasma, thedisclosure is by no means meant to be limiting in any such regard. Forexample, devices and techniques described and claimed herein can moregenerally be directed to the separation of components from a fluidmixture through spray drying. Such applications can include processingof protein as used in animal feed, processing as used in pharmacyapplications. More generally, the systems, devices and processesdescribed herein can be directed to treating mammalian blood products,to include veterinary applications.

One skilled in the art will realize the invention may be embodied inother specific forms without departing from the spirit or essentialcharacteristics thereof. The foregoing embodiments are therefore to beconsidered in all respects illustrative rather than limiting of theinvention described herein. Scope of the invention is thus indicated bythe appended claims, rather than by the foregoing description, and allchanges that come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

1. A spray drying collection device, comprising: an inlet port in fluidcommunication with the opposite end of a drying chamber; a filterseparating dried powder from humid air; and an exhaust port allowing thehumid air to exit the collection device.
 2. The spray drying collectiondevice of claim 1, further comprising an outer wall, in which the inletport and exhaust port are disposed along opposite sides.
 3. The spraydrying collection device of claim 2, wherein the filter is disposedwithin the outer wall.
 4. The spray drying collection device of claim 3,further comprising a filter support attaching the filter to the outerwall.
 5. The spray drying collection device of claim 1, the filter formsa pouch-shaped collection chamber.
 6. The spray drying collection deviceof claim 5, wherein the pouch-shaped collection chamber is sized toaccommodate dried powder resulting from processing of a single unit ofliquid sample of a volume of no more than about 450 ml (about 0.951pints).
 7. The spray drying collection device of claim 1, furthercomprising a rehydration fluid and means for selectively combining therehydration fluid with the dried powder.
 8. The spray drying collectiondevice of claim 2, wherein a volume defined by the outer wall is sizedto accommodate a single unit of liquid sample of a volume of no morethan about 450 ml (about 0.951 pints).
 9. The spray drying collectiondevice of claim 1, wherein the filter comprises a filter media capableof creating a sterile barrier.